Electron impact studies. VI. Mass spectra of esters and thioesters. Skeletal rearrangement on electron impact

Abstract
The mass spectra of representative series of simple alkyl acetoacetates, alkyl acetothioacetates, and some unsaturated esters derived from unsaturated alcohols or phenols are reported and discussed. The fragmentation schemes have been established by high resolution measurements, appropriate metastable ions, and by deuterium and 18O labelling. Many of the spectra show significant skeletal rearrangement fragments arising from either loss of carbon monoxide or carbon dioxide.